The author’s conclusion is just what he is ‘supposed’ to say.
Of course immigrants who truly wish to fully join and ar truly needed should be welcome. That has made our country and others prosper.
Accepting immigrants that don’t want to integrate and aren’t needed is a recipe for disaster. It’s so stupid that I can’t think of an example from history of it occurring.
It IS a common practice in history for invaders to drive vanquished before them to sap the defender’s resources.
Why?
You can have multiculturalism or mass immigration of groups - but not both without Balkanization.